Experimental investigation of repeated low velocity impact on GLARE with various energy levels

In this study, an experimental investigation of repeated low velocity impact is performed on GLARE using drop weight testing machine. After the first impact on the plate, the second impact energy decreases and stays constant until the last impact. Damage due to repeated impact is investigated using visual inspection and C-scan. Three categories namely, no damage, small damage and serious damage are happened as a result of the first impact on the plate. The number of impacts required for the penetration is increased with decrease of the second impact energy. The threshold limit energy is defined as the maximum impact energy in repeated impact after the first impact which causes no damage on the specimen. For the successive impact energy larger than the threshold limit energy, the number of impacts becomes important, while for the successive impacts energies smaller than threshold limit energy, the number of impact has inconsiderable effect on damage occurrence.